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Lukáš Machlica and Zbyněk Zajíc and Aleš Pražák : Methods of Unsupervised Adaptation in Online Speech Recognition . SPECOM'2009 Proceedings, p. 448-453, 2009.

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This paper deals with adaptation techniques based on maximum likelihood linear transformations, which are well suited for the task of on-line recognition. When transcriptions are available before the system starts running, we are speaking about supervised adaptation. In unsupervised adaptation the transcriptions have to be computed in the first pass of the recognition process. This is often the case in on-line recognition, where data are gathered continuously. Because the system does not work perfectly it is suitable to assign a certainty factor (CF) to each of the transcriptions. Only data that transcriptions have high CF are used for the adaptation. In the on-line recognition, the adaptation (in the sense of updating transformation formulas) has to be performed iteratively whenever the amount of recognized data reaches the pre-specified level. When small amount of adaptation data is available, it is suitable to involve regression trees to cluster similar model parameters. It is quite useful to adapt both speech and silence parameters. Because speech and silence have very different characteristics, we have separated them into two different clusters. Presented methods have been tested on short term recordings and results have proved the suitability of the proposed approach.

Detail of publication

Title: Methods of Unsupervised Adaptation in Online Speech Recognition
Author: Lukáš Machlica ; Zbyněk Zajíc ; Aleš Pražák
Language: English
Date of publication: 30 May 2009
Year: 2009
Type of publication: Papers in proceedings of reviewed conferences
Title of journal or book: SPECOM'2009 Proceedings
Page: 448 - 453
ISBN: 978-5-8088-0442-5
Date: 21 Jun 2009 - 25 Jun 2009
/ 2009-10-07 13:15:35 /


 author = {Luk\'{a}\v{s} Machlica and Zbyn\v{e}k Zaj\'{i}c and Ale\v{s} Pra\v{z}\'{a}k},
 title = {Methods of Unsupervised Adaptation in Online Speech Recognition},
 year = {2009},
 journal = {SPECOM'2009 Proceedings},
 pages = {448-453},
 ISBN = {978-5-8088-0442-5},
 url = {},